1. Field of Invention
The present invention relates to a process for the preparation of chirally pure β-amino alcohol of general formula 1A. More particularly, the present invention relates to enantioselective synthesis of N-sulfonyl n-amino alcohols effective in reduction of β-amyloid (Aβ) production in vivo in the patient of Alzheimer's disease (AD). In particular, the present process involves proline catalyzed asymmetric α-aminooxylation and α-amination of aldehyde (4) to give the corresponding amino alcohol (9) a key intermediate for the preparation of compound of formula (1A) with an overall yield of 45.2% and 98% ee.
wherein, R1 and R2=ethyl, methyl, isopropyl or trifluoromethyl.